ABB RER670 - How to Wire the Transformer Differential Protection to the IED Using Cts

Transformer connection – example 5
GUID-B0B4EFFC-DA6B-47F3-8B72-70255DC783F9 v2
I
U
I
v
I
s
110kV
15kV
U
S
V
110/15kV
IEC15000174-3-en.vsdx
R
IEC15000174 V3 EN-US
Figure 36: Transformer connection – example 5
The starpoint of the 110/15kV railway transformer can either be earthed (via coil)
or isolated.
For information on how to arrange the differential protection for this transformer,
see example 2.
6.2.4.2 How to wire the transformer differential protection to the IED using
CTs
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Here are two examples of how to wire and connect a star-connected, two-phase CT
(on the high-voltage side) and a one-phase CT (on the low-voltage side) to the IED
for protection of a railway power transformer (shown in Figure
31) using the
T1PPDIF function.
For the correct terminal designations, see the connection diagrams
valid for the delivered IED.
Section 6 1MRK 506 375-UEN A
Differential protection
90 Railway application RER670 2.2 IEC
Application manual